The explosion of glyphosate use in recent years has been driven primarily by the widespread adoption of GMO corn and soybeans. These GMO plants have been genetically engineered to withstand blasts of this powerful herbicide and kill the weeds around them. The use of glyphosate in the U.S. has increased by more 500 million pounds between 1996 and 2011.

According to an article in the Lancet, “[Glyphosate] use has increased sharply with the development of genetically modified glyphosate-resistant crop varieties. Glyphosate has been detected in air during spraying, in water, and in food.”

Scientists from 11 nations met at the International Agency for Research on Cancer, a branch of the World Health Organization, earlier this month to assess the likelihood that certain pesticides used in industrial agriculture would cause cancer.

They decided to classify glyphosate as a “probable carcinogen,” a conclusion that built on IARC’s conclusion last year that some evidence linked glyphosate to an increased risk of non-Hodgkin lymphoma, a type of blood cancer.

Because farmers have relied so heavily on glyphosate, many of them are now dealing with “superweeds” – varieties of weeds that no longer die when sprayed – and are turning to more toxic weed killers like 2,4-D. Dow’s Enlist Duo is a mixture of glyphosate and 2,4-D.